Refractory lining



W. W. URMETZ REFRACTORY LINING l Filed Jan. 8, 1943 Dec. 23, 1947.

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REFRACTORY LINING i h? INVENToR. .N BSW/u rep WMaMfrz 4me/vers Patented Dec. 23, 1947 REFRACTORY LINING Walter W. Urmetz, Parma, Ohio, assignor to The y Ferro Engineering Company, Cleveland, Ohio,

a corporation of Ohio Application January 8, 1943, Serial No. 471,676

This invention relates to improvements in refractory linings, that is to say refractory linings for metallic Walls or surfaces such for example as the interior wall surfaces of composite hot tops.

Some hot tops, particularly hot tops for large slab molds in which are cast ingots for the plate and strip mills of the steel industry, have at least one relatively long horizontal dimension, .and the walls parallel to that dimension are of such extent that it is not practical to use a single block of refractory to reach entirely from one corner to the other. Accordingly, in securing the two or more courses of blocks in place on a long side wall, it has become a relatively common expedient to employ dovetail keys on the metal casing and half dovetail recesses in the blocks, as illustrated in Charman Patent No. 1,969,726. When the slab molds are of moderate size, one key per course in the middle of a side furnishes sufficient greater dimensions are coming into use, and in hot tops for such molds the blocks for use with a single metal key are of course becoming correspondingly longer. There are practical manufacturing limits to th-e -length of refractory blocks of this character. Consequently it came about that two or mog.A keys were employed on a side. But even then' block size tended to be large, which is not conducive to` the maintenance of quality, dimensions, and atness.

When a plurality of keys were employed on a wall surface, blocks had to be slid into place between keys from the top of the casing. Ii the keys were relatively short, as was usually the case, the recesses in a block would overlap the key and in some cases molten steel would get behind the block into the recesses.

In prior constructions of this kind also the corner blocks are bevelled key blocks and must be slid into position from the top of the casing after the side and end blocks are in place. Consequently when it became necessary to replace a block in the lower row or tier of blocks, it was necessary to first remove a corner block of the upper tier before the corresponding corner block of the lower tier could be removed, and when it became necessary to removel a side block from between two metal keys, it was necessary to iirst remove the corresponding block of the upper course in order that the lower course block might be slid upward between keys.

Lining blocks employed in carrying out my invention may be made in small units with less shrinkage and distortion. The manner of install- 'i claims. (ci. 22-147) 2 r. ing the blocks is such 'that the lower course which fails earliest can be replaced without disturbing the upper course. Blocks of special shape, such as are used for hot top linings, must be made by hand, and smaller blocks of this type are sounder because smaller wauks of clay can be more easily handled andV better compacted. Greater standardization of blocks can be achieved because the smaller blocks can be used in hot tops of many diierent designs and sizes, whereas heretofore many hot tops had their own blocks exclusively. Easier handling and faster laying up of the blocks can be obtained with the smaller size such as I employ, andthe system of keying which the present invention utilizes has been demonstrated in practice to provide supej rior holding power and to result in better lining life. Y

Accordingly, objects of the invention are to provide linings for large hot tops in which refractory blocks of moderate size may be used, to

improve and perfect the retention of the lining in the metal casing, to speed up the insertion of the linings, to enable the manufacture of a better grade of lining` blocks, to reduce the amount of olf-size blocks due to close tolerances of previous designs, to enable the user to replace damaged blocks without disturbing the entire lining, and to enable the steel industry to use larger hot tops without regard to limitations in block size.

Other objects and features of novelty will appear as I proceed with the description of those embodiments of the invention which, for the purposes of the present application, I have illustrated in the accompanying drawings, in which Fig. 1 is a horizontal sectional view of a hot top casing constructed in accordance with the invention, the refractory lining in position therein being indicated by broken lines. The view is taken substantially on line I-I of Fig. 2.

Fig. 2 is an elevational sectional view taken substantially on the line 2-2 of Fig. 1. v

Fig. 3 is a vertical sectional view taken on the line 3--3 of Fig. 2.

Fig. 4 is an elevational view on a somewhat larger scale showing the lining blocks for one side of the casing illustrated in the previous tlgures, the pairs of blocks being separated in order to better show their side edge formations.

Fig. 4.

Fig. 6 is an elevational view on a still larger scale showing a single joint between blocks.

Fig. 7 is a bottom plan View, partly in section, on the line 'I--I of Fig. 6.

Fig. 5 is a plan View of the blocks illustrated in than the spacing of the keys.

Fig. 8 is a fragmental sectional view on the line 8-8 of Fig. 6.

Fig. 9 is a view corresponding to the sectional portion of Fig. 7, showing a modified form of joint; and

Figs. and 11 are elevational and cross-sectional views respectively of a further modified form of joint.

Referring first to the preferred form of the invention illustrated in Figs. 1 to 8 inclusive, I0 represents a hoi'l top casing having an internal ledge Il upon which rests the lower tier or row of refractory blocks making up the semi-permanent lining of the hot top. These blocksare locked in place by the novel means hereafter to be described. The casing illustrated is designed for use with two tiers or rows of lining blocks, but as will be apparent to those skilled in the art, the invention is equally applicable to a single tier or to more than two tiers.

Extending forwardly from the walls of the casing I0 there are keys I2, which may be cast integral with the walls, as indicated in Fig. 7, or may be separately formed and attached to the walls by means of screws I3 as indicated in Figs. 1, 2 and 3. I have shown keys on the end walls of the casing in Fig. l, but they may be omitted where the hot top is narrow enough to permit the convenient use of a single block for each tier of the end wall lining.

Referring particularly to Figs. 4 and 5, the lining for one side wall may comprise end blocks I4, I5, I6 and I'I and a plurality of blocks I8. The latter blocks may be -identical if the height of the blocks in the two tiers is the same. Each of the blocks I8 has an under lap I9 at one end and an over lap at the other end. The under lap I9 has a cutout 2| such that the remaining portions may straddle the corresponding key. The over lap 20 extends the full width of the block and is adapted to overlie the under lap portions I9 of the next adjacent block. For an intermediate portion of its width, however, the block is undercut as indicated at 22 and is provided with an inclined surface 23 of the same slope as the undercut surface of key I2, so that the surface 23 may be pushed into close engagement with the undercut surface of the key for holding against the casing wall that end of the block.

It is not entirely essential that the key be located midway between the side edges of the blocks as illustrated, but that location is preferred in order that the over lap may engage the under lap symmetrically and thus hold both side edges of the underlapped block rmly against the casing wall. In this form of the invention, in which the central portion of the under lap is cut away and the remaining portions straddle the key, the key is covered entirely by the over lap, as clearly shown in Fig. '7.

Inasmuch as it is impossible in a practical commercial sense to hold the dimensions of a refractory block to close limits, the undercut portion or cavity 22 is formed with a. little greater height than the height of key I2, the cutout 2I is a little longer than the key, the combined thickness dimension of the under lap I9 and over lap 20 is a little less than the thickness of the block I 8, and the length of each block is a little less The resulting cracks are filled in with suitable high temperature cement, as illustrated in the drawings..

Blocks I4 and I5 are formed on their righthand edges, as viewed in Figs. 4 and 5, with over laps 20 and undercuts 22 identical with the same formations in blocks IB, while the left-hand edges of these blocks I4 and I5 are bevelled, as shown at 24 and 25, in order to cooperate with corner blocks 26. The end blocks I6 and I'I have under laps I9 and cutouts 2| identical with the same formations in blocks I8 and bevelled edges 2'I and 28, the latter to engage with corner blocks 25.

In assembling the lower course of a side wall lining the block II is first put in place, that is to say its right-hand edge may be pushed laterally into engagement with the adjacent corner block and its other edge swung out agaist the casing wall, the key being cleared by the cutout 2I. Then thenext adjacent block is pushed sidewise to bring its inclined surface 23 into engagement with the undercut surface of the key, when its over lap 20 will overlie the under laps I9 of block I1 and lock the left edge of that block against the wall. The left edge of the said block I8 is then swung against the wall, its cutout 2I clearing the second key. The block I8 next toward the left is then mounted in the same manner, after which the block I5 is put in position by a similar procedure. This latter operation is performed before the corner block on that end wall is slipped into position. The lining blocks of the bottom course for the other walls may then be assembled in a similar manner, proceeding always toward the left. If preferred, however, all four bottom course wall linings may be assembled before any of the corner blocks of that course are slid into place. Thereafter the upper course blocks may be assembled with a like procedure.

I depart from thecustomary practice of using bevelled key Iblocks at the corners of the lining. The blocks 26 in the illustrated case have parallel joint or mortar surfaces. In any case the lines in the cross-sections representing the joint or mortar surfaces will be parallel. Accordingly, they may be slid into place laterally. High temperature cement, indicated at 9 in Figs. l and 5, is relied upon to hold these blocks against displacement inwardly. This has been found to be sufficient in view of the small size of the corner blocks and in view of the fact that the load upon them is relatively light.v A corner block in a lower course can therefore be readily replaced without disturbing the corresponding corner block in the course above, and this is highly advantageous.

-In Fig. 9 I have illustrated a modified form of joint in which the shiplap occurs entirely to one side of the key I2. In this form the under lap 30 as well as the over lap 3| is continuous from one side to the other of the block and the under lap abuts against the straight wall of the key. In other words, there is no cutout like the cutout 2| of the first described form. The over lap 3|, instead of terminating flush with the perpendicular Wall of the key, extends beyond that wall. In other respects, both as to construction and method of assembly, this joint is like that of the first described form of the invention,

In Figs. l0 and l1 a further modification is illustrated wherein both of the blocks 32 and 33 are undercut to accommodate the key I2. By this expedient the depth of the undercut in the block 32 is reduced as compared with the undercuts in the previously described forms. Here the :block 33 has a rpair of under laps 34 extending forward from the visible seam line 35 and an undercut 36 extending rearwardly from that line. The key I2 is received within the undercuts and straddled by the under laps 34. The over lap ateatro 37 on block 32 extends throughout the width of the block and only halfway across the key. Its inclined surface 38 terminates substantially flush with the over lap 31.

Having thus described my invention what I claim is:

1. In a hot top, a generally rectangular metallic casing, a refractory lining therefor cornprising side and end wall blocks having bevelled edges adiacent the corners of the casing, and comprising corner blocks in any cross-section of which the lines representing the joint or mortar surfaces will be parallel, said blocks fitting between the bevelled edges of the adjacent side and end wall blocks, whereby the corner blocks may be inserted laterally and cemented to hold the adjacent side and end wall blocks in place.

2. In a hot top, a generally rectangular casing, a refractory lining therefor comprising end wall blocks and a plurality of blocks for each side wall, the side and end wall blocks having bevelled edges adjacent the corners of the casing, means at the joints between side wall blocks for holding those blocks at said joints against the casing wall, said lining comprising also corner blocks in any cross-section of which the lines representing the joint or mortar surfaces will be parallel, said blocks fitting between the bevelled edges of the adjacent side and end wall blocks,A

whereby the corner blocks may be inserted laterally and cemented to hold the adjacent side and end wall blocks in place.

3. In a hot top, a metal casing having along an inner wall thereof two or more parallel preset undercut keys, lining blocks of a given course having shiplap joints at said keys, said keys being shorter than the width of the blocks, Vsaid lining being undercut at the joints to cover said keys, the edge of each block adjoining an undercut side of a key having an overlap portion and a portion underlying the key and the edge of each block adjoining the opposite side of a key having an underlap cut away to accommodate the key, said underlap underlying the Aoverlap of the adiacent block, certain of said lining blocks adjoining a key on one side only and laterally removable and replaceable lining block means `abutting said last named blocks for preventing sidewise movement thereof.

4. In a hot top, a metal casing having along an inner wall. thereof two or more parallel preset undercut keys, lining blocks of a given course having shiplap joints at said keys, said keys being shorter than the width of the blocks and positioned intermediate the ends of the joint edges, said lining being undercut at the joints I to cover said keys, the edge of each vblock adjoining an undercut side of a key having an overlap portion and a portion underlying the key and the edge of each block adjoining the opposite side of a key having an underlap portion cut away to straddle said key, said underlap underlying the overlap of the adjacent block, certain of said lining blocks adjoining a key on one side only and removable and replaceable lining lblock means abutting said last named blocks for preventing sidewise movement thereof.

5. In a hot top, a metal casing having along an inner wall thereof two or more parallel preset undercut keys, lining blocks of a given course having shiplap joints at said keys, said keys being shorter than the width of the blocks, the edge of each block adjoining an undercut side of a key having an overlap portion, a portion undercut to cover the adjacent key and a portion underlying said key and the edge of each block adjoining the opposite side of a key having an underlap cut away to accommodate the key, the remaining portions of the underlap underlying l the overlap of the adjacent block, certain of said lining blocks adjoining a key on one side only and removable and replaceable lining block means abutting said last named blocks for preventing sidewise movement thereof.

6. In a hot top, a metal casing having along an inner wall thereof two or more parallel preset undercut keys, lining blocks of a given course having shiplap joints at said keys, said keys being shorter than the width of the blocks and positioned intermediate the ends of the joint edges,

the edge of each block adjoining an undercut side of a key having an overlap and being underout to cover the said key and having a portion underlying said key, and the edge of each block adjoining the opposite side of a key having an underlap cut away to straddle the key, the remaining portions of the underlap underlying the overlap of the adjacent block, certain of said lining blocks adjoining a key on one side only u and removable and replaceable lining block means abutting said last named blocks for preventing sidewise movement thereof. A

7. In a hot top, a metal casing having along an inner wall thereof two or more parallelv preset keys, lining blocks of a given course having shiplap joints at said keys, each of said keys being perpendicular to the casing wall on one side and undercut on the other side. the edge of each block adjoining the undercut side of a key having an overlap portion and a portion underlying that side of the key, and the edge of each block adjoining the perpendicular side of a key having an underlap a portion of which is perpendicular to the wall and adjoins the perpendicular side of the key, certain of said lining blocks adjoining a key on one side only and laterally removable and replaceable lining block means abutting said last named blocks for preventing sidewise move ment thereof.

WAL'I'ER w. URMETZ.

REFERENCES CITED The following referencesl are of record in the 5 file of this patent:

UNITED STATES PATENTS Number Name Date 466,742 Lanyon Jan. 5, 1892 477,746 Elterich June 28, 1892 530,4 24 Keating Dec. 4, 1894 1,341,977 Gates June 1, 1920 1,454,859 Raw May 15, 1923 1,689,175 Ramage Oct, 23, 1928 1,969,726 Charman Aug. 14, 1934 FOREIGN PATENTS Number Country 'Date 4,905 Great Britain June 1903 2,556 Great Britain Apr. 20, 1905 

